浅谈萘法制苯酐项目中蒸汽夹套管的配管设计

Piping Design of Steam Jacketed Tube in the Project of Preparing Phthalic Anhydride from Naphthalene

在萘法制苯酐装置中,因为原料和产品的熔点较高,需要大量的蒸汽夹套管伴热。项目中选用内管焊缝外露型夹套管(半夹套)伴热,以满足被伴热介质为有毒介质的要求;选用夹套管时管道转向处改为一端盲法兰的三通型式,以满足经常性检修的要求;选用中压蒸汽替代低压蒸汽作为伴热介质,以解决内管温度远高于外管时夹套端部结构受力过大等问题。

In the device of preparing phthalic anhydride from naphthalene, a lot of steam jackets for heat tracing are needed because of the high melting points of raw materials and products. Selects the jacketed piping with exposed inner tube welds（part jacketed piping） for heat tracing to meet the requirement of the toxic heated medium. Selects the tee with a blank flange end as the jacketed tube steering to meet the demand of the frequent maintenance. Selects medium pressure steam instead of low pressure steam as the heating medium in order to solve the problem of excessive force at the end of jacketed piping when the temperature of inner tube is much higher than that of the outer pipe.